| 1 | module Array = ArrayLabels |
| 2 | module List = ListLabels |
| 3 | |
| 4 | module type TREE = sig |
| 5 | type ('k, 'v) t |
| 6 | |
| 7 | val empty : ('k, 'v) t |
| 8 | |
| 9 | val set : ('k, 'v) t -> k:'k -> v:'v -> ('k, 'v) t |
| 10 | |
| 11 | val get : ('k, 'v) t -> k:'k -> 'v option |
| 12 | |
| 13 | val member : ('k, 'v) t -> k:'k -> bool |
| 14 | |
| 15 | val to_dot : ('k, 'v) t -> k_to_string:('k -> string) -> string |
| 16 | end |
| 17 | |
| 18 | module BinaryTree : TREE = struct |
| 19 | type ('k, 'v) t = |
| 20 | | Node of 'k * 'v * ('k, 'v) t * ('k, 'v) t |
| 21 | | Leaf |
| 22 | |
| 23 | let empty = Leaf |
| 24 | |
| 25 | let rec set t ~k ~v = |
| 26 | match t with |
| 27 | | Leaf -> Node (k, v, Leaf, Leaf) |
| 28 | | Node (k', v', l, r) when k < k' -> Node (k', v', set l ~k ~v, r) |
| 29 | | Node (k', v', l, r) when k > k' -> Node (k', v', l, set r ~k ~v) |
| 30 | | Node (k, _, l, r) -> Node (k, v, l, r) |
| 31 | |
| 32 | let rec get t ~k = |
| 33 | match t with |
| 34 | | Leaf -> None |
| 35 | | Node (k', _, l, _) when k < k' -> get l ~k |
| 36 | | Node (k', _, _, r) when k > k' -> get r ~k |
| 37 | | Node (_, v, _, _) -> Some v |
| 38 | |
| 39 | let rec member t ~k = |
| 40 | match t with |
| 41 | | Leaf -> false |
| 42 | | Node (k', _, l, _) when k < k' -> member l ~k |
| 43 | | Node (k', _, _, r) when k > k' -> member r ~k |
| 44 | | Node _ -> true |
| 45 | |
| 46 | let to_edges t = |
| 47 | let rec to_edges_from k1 t = |
| 48 | match t with |
| 49 | | Leaf -> [] |
| 50 | | Node (k2, _, l, r) -> |
| 51 | (k1, k2) :: ((to_edges_from k2 l) @ (to_edges_from k2 r)) |
| 52 | in |
| 53 | match t with |
| 54 | | Leaf -> [] |
| 55 | | Node (k, _, l, r) -> (to_edges_from k l) @ (to_edges_from k r) |
| 56 | |
| 57 | let to_dot t ~k_to_string = |
| 58 | let (edges, _) = |
| 59 | List.fold_left (to_edges t) |
| 60 | ~init:("", "\n") |
| 61 | ~f:(fun (edges, sep) (k1, k2) -> |
| 62 | let k1, k2 = k_to_string k1, k_to_string k2 in |
| 63 | (Printf.sprintf "%s%s %S -> %S;\n" edges sep k1 k2, "") |
| 64 | ) |
| 65 | in |
| 66 | "digraph G {" ^ edges ^ "}" |
| 67 | end |
| 68 | |
| 69 | let () = |
| 70 | let tree_a = BinaryTree.empty in |
| 71 | let tree_a = BinaryTree.set tree_a ~k:"k1" ~v:"v1" in |
| 72 | let tree_a = BinaryTree.set tree_a ~k:"k2" ~v:"v2" in |
| 73 | assert (BinaryTree.member tree_a ~k:"k1"); |
| 74 | assert (BinaryTree.member tree_a ~k:"k2"); |
| 75 | assert (Some "v1" = BinaryTree.get tree_a ~k:"k1"); |
| 76 | assert (Some "v2" = BinaryTree.get tree_a ~k:"k2"); |
| 77 | let tree_b = |
| 78 | Array.fold_left (Sys.argv) |
| 79 | ~init:BinaryTree.empty |
| 80 | ~f:(fun t k -> BinaryTree.set t ~k ~v:()) |
| 81 | in |
| 82 | print_endline (BinaryTree.to_dot tree_b ~k_to_string:(fun x -> x)) |